1. Field of the Invention
The present invention relates generally to an orthopedic device for limiting limb motion. Particularly, this invention relates to an ankle-foot orthosis with a dual-adjustable stop system for quietly limiting the range of pivotal movement of the foot. Even more particularly, this invention relates to an ankle-foot orthosis with a single unit dual-adjustable stop system that allows for ease of manufacture. Still even more particularly, this invention relates to an ankle-foot orthosis with a dual-adjustable stop system that allows the angle of plantarflexion and dorsiflexion to be set and the pivotal movement of the foot permanently fixed.
2. Description of the Related Art
Hinged orthopedic braces having an adjustable range of pivotal movement, as disclosed by U.S. Pat. Nos. 5,022,390 (1991) and 5,328,444 (1994), both to Whiteside, are known in the art. The braces disclosed therein have adjustable stopping mechanisms to limit the range in pivotal movement of two hinged members of the brace relative to each other. The stopping mechanisms taught by the above-mentioned patents disclose an adjustable stop mechanism attached to one member of the brace and is positioned to come into contact with an abutment attached to the other member of the brace when the members are pivoted to a desired angle of restriction. As the wearer of a brace with this type of stopping mechanism takes a step, the stopping mechanism comes into contact with the abutment creating a loud clacking sound. This noise can be quite distracting or embarrassing to someone walking with the brace.
Other ankle-foot orthotic devices such as U.S. Pat. Nos. 5,399,152 (1995) to Habermeyer et al. and 5,429,588 (1995) to Young et al. disclose ankle foot orthoses designed to treat fractures and other injuries to the foot and ankle. Habermeyer discloses an apparatus that consists of two members pivotally connected. Each member provides surroundive fixation that is both removable and adjustable through the filling and evacuating of cushions within each member. Rear pivotal movement (plantarflexion) and front pivotal movement (dorsiflexion) are restricted by a bar with an attached abutment head contacting adjustable abutments located above and below the abutment head. One problem with this device is that the adjusting mechanism has multiple parts making it difficult and expensive to manufacture. Another problem with this device is that the parts are not easily replaceable by the wearer.
Young discloses an apparatus known in the art as a walker that consists of two members pivotally connected wherein plantarflexion and dorsiflexion are restricted between 22.5.degree. of plantarflexion and 22.5.degree. of dorsiflexion by adjustable screws contacting an upright side member. One problem with this device is that some wearers may require a greater range of motion than this device allows.
Still other foot and ankle devices such as U.S. Pat. Nos. 5,014,690 (1991) to Hepburn et al. and 5,144,943 (1992) to Luttrell et al. disclose dynamic splints which apply an adjustable force inducing either plantarflexion or dorsiflexion.
U.S. Pat. No. 5,044,360 (1991) to Janke discloses a foot ankle device with two members that are pivotally attached. Dorsiflexion and plantarflexion are restricted through the use of interchangeable cams, which have differing cam surfaces that come into contact with a rotatable stop. The unique shape of each interchangeable cam determines at what point or angle in plantarflexion or dorsiflexion the rotatable stop contacts the cam surface and limits range of motion.
U.S. Pat. No. 4,919,118 (1990) to Morris discloses a short leg walker which has a motion limiter consisting of a shaft pivotally attached to one of the walker's members and a sliding block pivotally attached to the remaining member. Restriction of plantarflexion and dorsiflexion occurs when the sliding block engages adjustable stop members, which are located above and below the sliding block. By adjusting the positions of the stop members, the range of motion can be limited accordingly.
There remains a need to provide a strong yet lightweight comfortable ankle-foot orthosis, which can effectively limit the ankle-joint against a wide range of pivotal movement and which is quiet in use. There also remains a need to provide a strong yet lightweight comfortable ankle-foot orthosis which has few parts and which is simple and inexpensive to manufacture. Additionally, there remains a need to provide a strong yet lightweight comfortable ankle-foot orthosis, which has dual-adjustable stop members that are easy to adjust and replace, which is concealable under clothing or footwear, and which is custom fit for the wearer. Still further, there remains a need to provide a strong yet lightweight comfortable ankle-foot orthosis that can set the angle of plantarflexion and dorsiflexion of the foot and that can permanently fix the pivotal movement of the foot.